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An introduction to quiet daily geomagnetic fields An introduction to quiet daily geomagnetic fields

On days that are quiet with respect to solar-terrestrial activity phenomena, the geomagnetic field has variations, tens of gamma in size, with major spectral components at about 24, 12, 8, and 6 hr in period. These quiet daily field variations are primarily due to the dynamo currents flowing in the E region of the earth's ionosphere, are driven by the global thermotidal wind systems, and...
Authors
W.H. Campbell

Morphology of sea-floor landslides on Horizon Guyot: application of steady-state geotechnical analysis Morphology of sea-floor landslides on Horizon Guyot: application of steady-state geotechnical analysis

Mass movement and erosion have been identified on the pelagic sediment cap of Horizon Guyot, a seamount in the Mid-Pacific Mountains. Trends in the size, shape and preservation of bedforms and sediment textural trends on the pelagic cap indicate that bottom-current-generated sediment transport direction is upslope. Slumping of the sediment cap occurred on and that the net bedload...
Authors
R. E. Kayen, W. C. Schwab, H.J. Lee, M.E. Torresan, J.R. Hein, P. J. Quinterno, L.A. Levin

Structures associated with strike-slip faults that bound landslide elements Structures associated with strike-slip faults that bound landslide elements

Large landslides are bounded on their flanks and on elements within the landslides by structures analogous to strike-slip faults. We observed the formation of thwse strike-slip faults and associated structures at two large landslides in central Utah during 1983-1985. The strike-slip faults in landslides are nearly vertical but locally may dip a few degrees toward or away from the moving...
Authors
R. W. Fleming, A. M. Johnson

The competition between thermal contraction and differentiation in the stress history of the Moon The competition between thermal contraction and differentiation in the stress history of the Moon

The scarcity of both extension and compression features on the Moon strongly constrains the history of the lunar radius—to variations of less than ±1 km over the past 3.8 Gyr. This limit has traditionally been interpreted as requiring a delicate balance between thermal contraction of the near‐surface and expansion of a substantial cold interior region. Recent theories of lunar origin (e...
Authors
Randolph L. Kirk, David J. Stevenson
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